Fundus autofluorescence in eyes with dry and wet form of age-related macular degeneration (AMD) – clinical implications

Introduction
To evaluate retinal pigment epithelium (RPE) and photoreceptors layer integrity in different stages of AMD based on fundus autofluorescence imaging and to correlate autofluorescence images with visual acuity.

Material and methods
322 eyes of 200 patients with different forms and stages of AMD were studied. Mean age was 70 years (49-91 years). Apart from complete ophthalmologic examination patients were examined every 6 months by using a confocal scanning ophthalmoscope HRA2. Follow-up period ranged from 1 to 40 months (mean – 18 months).

Results
In 116 eyes with early AMD punctuate changes in autofluorescence images were observed while in 22 eyes (16%) no distinct changes were present. In 52 eyes (62%) with wet AMD normal or near normal autofluorescence signal was present and 34 eyes (38%) with wet AMD had changes in autofluorescence signal corresponding with choroidal neovascularisation (CNV) area. In the group of eyes with autofluorescence changes in the CNV area median BCVA was 0.1 and in the group without autofluorescence changes within the CNV area – 0.4. All eyes with disciform scar were characterized by uneven autofluorescence signal decrease in scar area with increased signal in surroundig area. Eyes with geographic atrophy (GA) had lack of autofluorescence signal corresponding to RPE atrophy and in 40 cases (95%) increase autofluorescence signal junctional to GA was noted.

Conclusions
Fundus autofluorescence images of the AMD eyes varies greatly. Decrease of autofluorescence signal correlates with visual acuity decrease.